EMBER Modeling Files

air quality environmental regulatory

Description

These data are being released to support states in wildfire Exceptional Events demonstrations. EPA released fire impacts modeling data for the 2023 fire season called the Expedited Modeling of Burn Events Results (EMBER) in December 2024. EPA has updated the EMBER Dataset Tool on the EPA website to include summary tables and graphics four new years of EMBER data: 2021, 2022, 2024, and 2025. As part of the effort to update the EMBER data, we are posting the full model input and output files publicly here to aid state, local, and Tribal air agencies in constructing any potential Exceptional Events demonstrations. For more information about EMBER, see the following web page: https://www.epa.gov/air-quality-analysis/expedited-modeling-burn-events-results-ember

Update Frequency

As needed

License

These datasets are products of the U.S. Government and are intended for public access and use. Unless otherwise specified, all data produced by the U.S EPA is, by default, in the public domain and are not subject to domestic copyright protection under 17 U.S.C. § 105. More details on the U.S. Public Domain license are available here: http://www.usa.gov/publicdomain/label/1.0/

Documentation

Dataset Description for 2023: https://www.sciencedirect.com/science/article/pii/S2352340924011703

Managed By

U.S. Environmental Protection Agency

See all datasets managed by U.S. Environmental Protection Agency.

Contact

Simon.Heather@epa.gov

How to Cite

EMBER Modeling Files was accessed on DATE from https://registry.opendata.aws/epa-ember. EMBER Modeling Files was accessed on DATE from https://registry.opendata.aws/epa-ember. US EPA, 2026, "Development of the Expedited Modeling of Burn Events Results (EMBER) Datasets for 2021, 2022, 2024, and 2025", 454R26002

Resources on AWS

  • Description
    The data are organized into four yearly folders (2021 data, 2022 data, 2024 data, and 2025 data), each with the same directory structure:
    $YYYY (four digit year)
└── CMAQ
    ├── Emissions
    │   ├── Anthropogenic
    │   └── fires
    ├── Inputs
    │   ├── ICBC
    │   └── MCIP
    └── Outputs
    All files are NetCDF version 3 formatted files using I/O API (IOAPI) data structures.

    Emissions input files

    Emissions are split into two main directories, Anthropogenic and Fires.

    Anthropogenic includes all anthropogenic emissions, used in the base simulation as well as both zero-out simulations. The same anthropogenic emissions are used for the 2021 and 2022 simulations, so the files are only provided in the 2021 directory (the 2022 directory contains a README pointing there). Likewise, the same emissions are used for 2024 and 2025 for all sectors except ptegu. All emissions files from sectors other than ptegu are only provided in the 2024 directory (the 2025 directory contains a README pointing there).

    Subfolders:
    • Beis_inline — auxiliary files needed to run CMAQ with online biogenic emissions calculations
    • merged_nobeis_norwc — gridded emissions: all gridded sources except residential wood combustion and biogenic sources
    • rwc — gridded emissions: residential wood combustion
    • pt_oilgas — point source emissions: oil and gas exploration and production
    • ptegu — point source emissions: electric generating units
    • cmv_c3 or cmv_c3_36 — point source emissions: large ocean-going C3 class commercial ships
    • cmv_c1c2 or cmv_c3_36 — point source emissions: smaller C1 and C2 class commercial ships
    • othpt or canmex_point — point source emissions: sources located in Mexico and Canada
    • ptagfire (2024 only) — point source emissions: agricultural burning sources
    • ptnonipm (2021 and 2024) and ptnonipm_hr (2024 only) — point source emissions not included in another category; ptnonipm_hr comes from sources with hourly CEMS data
    Fires includes day-specific fire emissions for each simulation year.

    Subfolders:
    • ptfire_othna (2021 and 2022) — wildland and agricultural fires in Canada and Mexico
    • ptfire-canada (2024 and 2025) — wildfires in Canada
    • ptfire_mexona (2024 and 2025) — wildland and agricultural fires in Mexico
    • ptfire-rx — prescribed fires in the United States
    • ptfire-wild — wildfires in the United States
    Point source sectors include inln_mole files (emissions magnitudes) and stack_groups files (emissions location/stack characteristics). Gridded sectors include only emis_mole files (gridded emissions magnitudes).

    Meteorological input files

    Found in $YYYY/CMAQ/inputs/MCIP. Files are NetCDF version 3 formatted files using I/O API (IOAPI) data structures, provided for every day of the simulation. File type and variable descriptions: https://github.com/USEPA/CMAQ/tree/main/PREP/mcip

    Initial and boundary condition files

    Found in $YYYY/CMAQ/inputs/ICBC. Files are NetCDF version 3 formatted files using I/O API (IOAPI) data structures. Initial conditions are provided for April 1 of each simulation year; boundary condition files are provided for every day of the simulation. Descriptions: https://github.com/USEPA/CMAQ/tree/main/PREP/bcon and https://github.com/USEPA/CMAQ/tree/main/PREP/icon

    Gridded model output files

    For each simulation year, gridded daily layer-1 model outputs are provided for three simulations (base, zero fires, and zero Canada and Mexico fires) under $YYYY/CMAQ/outputs/:
    2021/CMAQ/outputs/
  Base:                  HR2DAY_CMAQv55_cb6r5_ae7_aq.36US3.35.basecase2021_2021_O3_PM25_01Apr2021to30Sep2021.nc
  Zero fires:            HR2DAY_CMAQv55_cb6r5_ae7_aq.36US3.35.noFires2021_2021_O3_PM25_01Apr2021to30Sep2021.nc
  Zero CA/MX fires:      HR2DAY_CMAQv55_cb6r5_ae7_aq.36US3.35.noCN-MXfires2021_2021_O3_PM25_01Apr2021to30Sep2021.nc

2022/CMAQ/outputs/
  Base:                  HR2DAY_CMAQv55_cb6r5_ae7_aq.36US3.35.basecase2022_2022_O3_PM25_01Apr2022to30Sep2022.nc
  Zero fires:            HR2DAY_CMAQv55_cb6r5_ae7_aq.36US3.35.noFires2022_2022_O3_PM25_01Apr2022to30Sep2022.nc
  Zero CA/MX fires:      HR2DAY_CMAQv55_cb6r5_ae7_aq.36US3.35.noCN-MXfires2022_2022_O3_PM25_01Apr2022to30Sep2022.nc

2024/CMAQ/outputs/
  Base:                  hr2day_merged_2024.2024basecase_AMD_36US3_35.v55_m3dry.Apr-Sep.keyvars.ncf
  Zero fires:            hr2day_merged_2024.EMBER_noFires_AMD_36US3_35.v55_m3dry.Apr-Sep.keyvars.ncf
  Zero CA/MX fires:      hr2day_merged_2024.EMBER_noCA-MXfires_AMD_36US3_35.v55_m3dry.Apr-Sep.keyvars.ncf

2025/CMAQ/outputs/
  Base:                  hr2day_merged_2025.2025basecase_AMD_36US3_35.v55_m3dry.Apr-Sep.keyvars.ncf
  Zero fires:            hr2day_merged_2025.EMBER_noFires_AMD_36US3_35.v55_m3dry.Apr-Sep.keyvars.ncf
  Zero CA/MX fires:      hr2day_merged_2025.EMBER_noCA-MXfires_AMD_36US3_35.v55_m3dry.Apr-Sep.keyvars.ncf
    Each output file is a NetCDF version 3 formatted file using I/O API (IOAPI) data structures, containing daily gridded concentrations from layer 1 of the model simulation, with the following variables:
    • O3_MDA8 — maximum daily 8-hour ozone concentrations
    • ATOTIJ_AVG — 24-hour average total PM2.5 concentrations
    Resource type
    S3 Bucket
    Amazon Resource Name (ARN)
    arn:aws:s3:::epa-ember
    AWS Region
    us-east-1
    AWS CLI Access (No AWS account required)
    aws s3 ls --no-sign-request s3://epa-ember/
    Explore
    Browse Bucket
  • Description
    Notification for the Ember bucket
    Resource type
    SNS Topic
    Amazon Resource Name (ARN)
    arn:aws:sns:us-east-1:127085394039:epa-ember-object_created
    AWS Region
    us-east-1

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